1. Field of the Invention
This invention relates to lattice systems for storage of information, and more particularly to a lattice system using interactive elements where the lattice is expanded or shifted to provide various functions, without the need for taking elements from the lattice or putting elements into the lattice.
2. Description of the Prior Art
Lattice file systems have been described previously in copending application Ser. No. 395,336, filed Sept. 7, 1973 now abandoned. These lattice systems are characterized by extremely high density storage in which interactive elements are crowded closely together to provide high capacity, high density storage. Because the lattice is a regular arrangement of interactive elements, each of the elements has to be coded in order to represent information. For instance, magnetic bubble domain lattices are described in that application where the coding is generally in terms of the wall magnetization properties of the individual bubble domains. Thus, the lattice system can be used as an information handling system having very high density.
In the lattice system described in that copending application, information is written into the lattice by entering new bubble domains into the lattice. The read operation is performed by removing bubble domains from the lattice and then detecting the different properties of the individual elements. To improve the average access time for information in the lattice, a column accessing scheme has been described in copending application Ser. No. 429,601, filed Jan. 2, 1974. This column accessing scheme uses a plurality of input and output ports for removing information from the lattice and placing new information into the lattice. Thus, the bubble domain lattice can be shifted in one direction to bring a column of elements into the appropriate input/output channel, after which these elements are removed from the lattice in a direction transverse to the original shifting direction of elements within the lattice. In general, the average access time to any element in the lattice is improved by a factor related to the number of input and output ports provided. Again, this improved accessing scheme relies on putting elements into the lattice and removing them from the lattice.
As was mentioned previously, all positions in a lattice have to be filled in order that the lattice be stable. This means that individual elements in the lattice have to be coded if they are to represent information. In the case of magnetic bubble domain lattices, and systems using these lattices, various types of coding arrangements have been utilized, most of which rely on the different properties associated with the wall magnetization states of the bubble domains. Such different coding schemes are described in aforementioned Ser. No. 395,336 and are additionally described in copending application Ser. No. 375,285, filed June 29, 1973 (now U.S. Pat. No. 3,899,779) and copending application Ser. No. 375,289, also filed June 29, 1973 (now U.S. Pat. No. 3,890,605. ) Another type of coding technique used in combination with the bubble domain lattice is exemplified by copending application Ser. No. 449,308, filed March 8, 1974, now U.S. Pat. No. 3,996,571. In this type of coding, the bubble domain lattice is used as a conveyor for information bubble domains in another magnetic medium, where the information bubble domains are magnetostatically coupled to the bubble domains in the lattice. The bubble domains in this other medium are the information carriers and they are coded in terms of presence/absence, as is conventionally done in bubble domain systems. Since the information bubbles are magnetically coupled to the lattice bubbles, movement of the lattice bubbles will cause movement of the information bubbles. Additionally, the information bubbles will have a density determined by the lattice bubbles so that high density storage is provided, without requiring the more complex coding techniques which are used when the lattice bubble domains are themselves coded.
The present invention provides a technique which overcomes problems associated with having to access interactive elements in a lattice. In the present technique, interactive elements do not have to be removed from the lattice and do not have to be entered into the lattice in order to provide the read/write functions. Additionally, block accessing of information can be obtained, or information can be obtained in a row by row fashion. This enhances the average access time for information. Also, the present technique relaxes margins which are placed on operations using a bubble domain lattice, since, as will be seen, many of the functions performed in lattice systems will be more easily performed because the lattice itself is relaxed. This may also aid in providing less coercivity since the movement of a plurality of bubble domains in a tightly packed array is no longer a requirement of the system. Additionally, different types of coding can be used in the present technique and multiple bubble domain layers can also be utilized.
Accordingly, it is a primary object of the present invention to provide an improved system using lattices of interactive elements, where the lattice can be maintained during the operation of such systems.
It is another object of this invention to provide a magnetic bubble domain lattice system, where a lattice of bubble domains is maintained while the spacings between bubble domains in the lattice is changed.
It is a further object of this invention to provide improved systems using lattices of interactive elements which have relaxed operational margins for the performance of various functions.
It is a still further object of the present invention to provide techniques for using lattices of interactive elements where the average access time for information is minimized, and in which block accessing can be provided.
It is another object of this invention to provide an improved lattice system using interactive elements, where different types of information coding can be easily used.
It is another object of the present invention to provide information handling systems using magnetic bubble domain lattices, where the inherent flexibility and stability of such lattices is directly utilized.